PB1937: UTILITY OF STERNAL BONE MARROW CELL MORPHOLOGY EVALUATION FOR DIAGNOSTIC CATEGORIZATION IN PATIENTS WITH ACQUIRED HYPOCELLULAR BONE MARROW FAILURE SYNDROMES
Authors: J. Chen, T. Qin, S. Qu, P. Zhang, L. Pan, B. Li, Z. Xiao, Z. Xu
Journal: HemaSphere (2022)

Background: Bone marrow failure syndromes (BMFS) are a group of heterogeneous diseases characterized by pancytopenia due to dysfunctional bone marrow elements. Approximately 15%-20% of patients with MDS presenting with marrow hypoplasia for age would be incorrectly categorized as AA, which the pathobiology and prognosis are distinct from hypoplastic MDS (hypo-MDS). The hematopoiesis of sternal bone marrow is typically more active than the ilium. Aims: To assess the diagnostic value of sternal bone marrow cell morphology in patients with acquired hypocellular bone marrow failure syndromes (BMFS) characterized by normal cytogenetics and develop a predictive scoring system to identify these patients that needed to perform sternal bone marrow evaluation. Methods: Between June 2014 and January 2019, 194 eligible patients with pre-sternum diagnosis of acquired hypocellular BMFS in our center were retrospectively reviewed. Binary logistic regression was used to develop a predictive scoring system. Results: In 152 patients (78.4%) with pre-sternum diagnosis of AA, sternal bone marrow evaluation confirmed a post-sternum diagnosis of AA, hypo-MDS, idiopathic cytopenia of undetermined significance (ICUS), and clonal cytopenia of undetermined significance (CCUS) in 50% (76/152), 42.8% (65/152), 3.3% (5/152) and 3.9% (6/152), respectively. In 29 patients (14.9%) with pre-sternum diagnosis of ICUS, a post-sternum diagnosis of ICUS and hypo-MDS were identified in 75.9% (22/29) and 24.1% (7/29) patients, respectively. In 13 patients (6.7%) with pre-sternum diagnosis of CCUS, sternal bone marrow evaluation confirmed a post-sternum diagnosis of CCUS and hypo-MDS in 69.2% (9/13) and 30.8% (4/13) patients. Disease-related risk of 76 patients with a post-sternum diagnosis of hypo-MDS were assessed by the revised version of International Prognostic Scoring System (IPSS-R), included 30 (39.5%) with low risk, 44 (57.9%) with intermediate, and 2 (2.6%) with high risk. Patients with post-sternum diagnosis of hypo-MDS showed a significantly difference in five-year survival compared with patients with post-sternum diagnosis of AA (98.6% vs 86.1%, p=0.005). Patients with ICUS/CCUS showed no difference in overall survival (OS) compared with AA and hypo-MDS (p=0.095 and p=0.480, respectively). A 4-items predictive scoring system to identify hypocellular BMFS patients that needed to perform sternal bone marrow evaluation was developed, including age>60 years (OR=6.647, 95%CI 1.954-22.611, p=0.002, 2 points), neutrophil alkaline phosphatase (NALP) score≤160 (OR=2.654, 95%CI 1.214-5.804, p=0.014, 1 point), abnormal erythroid markers evaluated by flow cytometry on iliac bone marrow (OR=6.2, 95%CI 1.165-32.988, p=0.032, 2 points), and DAT (DNMT3A, ASXL1, TET2) genes mutation (OR=4.809, 95%CI 1.587-14.572, p=0.005, 1 point). The AUC was 0.730 (95%CI 0.643-0.816) when the total scores ≥2 points. Image:Summary/Conclusion: Patients with a pre-sternum diagnosis of acquired hypocellular BMFS characterized by normal cytogenetics may not reach accurate diagnostic categorization without sternal bone marrow cell morphology evaluation, which could be considered a diagnostic tool for these patient population. We developed a predictive scoring system and when the total scores≥2 points, sternal bone marrow evaluation should be performed for accurate diagnostic categorization that is critical to optimal patient care.